U.S. patent application number 13/823585 was filed with the patent office on 2013-08-08 for semi-automatic tea maker.
This patent application is currently assigned to KONINKLIJKE PHILIPS ELECTRONICS N.V.. The applicant listed for this patent is Rogier Enrico De Haas, Gerrit Jan Jirnsum. Invention is credited to Rogier Enrico De Haas, Gerrit Jan Jirnsum.
Application Number | 20130199377 13/823585 |
Document ID | / |
Family ID | 43760084 |
Filed Date | 2013-08-08 |
United States Patent
Application |
20130199377 |
Kind Code |
A1 |
Jirnsum; Gerrit Jan ; et
al. |
August 8, 2013 |
SEMI-AUTOMATIC TEA MAKER
Abstract
Tea maker (100) comprising a controller (332) operably connected
to a heating element (222) for heating water in a water
compartment, a temperature sensor (224), a tea filter presence
sensor (226) for detecting the insertion of a tea filter into the
water compartment, and user notification means, the controller
being configured to heat water in the water compartment to an
initial steeping temperature; to detect whether the water has been
heated to the initial steeping temperature; to notify a user that
the water has been heated to the initial steeping temperature, and
that steeping may be initiated by insertion of the tea filter; and
once the user has been notified to insert the filter, to maintain
the temperature of the water within a certain range of the initial
steeping temperature until either a certain waiting period lapses,
or insertion of the tea filter is detected within said waiting
period.
Inventors: |
Jirnsum; Gerrit Jan;
(Eindhoven, NL) ; De Haas; Rogier Enrico;
(Eindhoven, NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Jirnsum; Gerrit Jan
De Haas; Rogier Enrico |
Eindhoven
Eindhoven |
|
NL
NL |
|
|
Assignee: |
KONINKLIJKE PHILIPS ELECTRONICS
N.V.
Eindhoven
NL
|
Family ID: |
43760084 |
Appl. No.: |
13/823585 |
Filed: |
October 18, 2011 |
PCT Filed: |
October 18, 2011 |
PCT NO: |
PCT/IB2011/054631 |
371 Date: |
March 14, 2013 |
Current U.S.
Class: |
99/282 ;
99/285 |
Current CPC
Class: |
A47J 31/52 20130101;
A47J 31/5253 20180801; A47J 27/212 20130101; A47J 27/2105 20130101;
A47J 31/002 20130101; A47J 31/525 20180801; A47J 31/20
20130101 |
Class at
Publication: |
99/282 ;
99/285 |
International
Class: |
A47J 31/00 20060101
A47J031/00; A47J 31/20 20060101 A47J031/20 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 27, 2010 |
EP |
10189066.3 |
Claims
1. A tea maker comprising: a water compartment; a tea filter that
is at least partly insertable into the water compartment; a heating
element, configured to heat water contained in said water
compartment; a temperature sensor, configured to generate a
reference signal reflecting the temperature of the water contained
in said water compartment; a tea-filter-presence sensor, configured
to detect insertion of the tea filter into the water compartment;
user notification means; a controller, operably connected to the
heating element, the temperature sensor, the tea-filter-presence
sensor and the notification means, and configured to heat water
contained in the water compartment in accordance with a
predetermined temperature/time profile that is at least partly
defined by an initial steeping temperature; to detect whether the
water has been heated to the initial steeping temperature in
accordance with the predetermined temperature/time profile; to
notify a user by means of the notification means that the water has
been heated to the initial steeping temperature, and that steeping
may be initiated by insertion of the tea filter; characterized in
that the controller is further configured, once the user has been
notified to insert the filter, to maintain the temperature of the
water within a certain range of the initial steeping temperature
until a certain waiting period lapses, unless insertion of the tea
filter is detected by means of said tea-filter-presence sensor
within said waiting period, in which case the controller is
configured to maintain the temperature of the water within said
range of the initial steeping temperature until the insertion of
the tea filter is detected.
2. The tea maker according to claim 1, wherein the range within
which the controller is configured to maintain the temperature of
the water once it has reached the initial steeping temperature is
the initial steeping temperature .+-.5.degree. C.
3. The tea maker according to claim 1, wherein the waiting period
during which the controller is configured to maintain the
temperature of the water within a certain range of the initial
steeping temperature, is not more than 60 minutes, preferably not
more than 30 minutes.
4. The tea maker according to claim 1, wherein the controller is
further configured to shut off the tea maker when the waiting
period has elapsed without prior detection of insertion of the tea
filter.
5. The tea maker according to claim 1, wherein the controller is
further configured: to determine, during heating the water to the
initial steeping temperature, an increase in the temperature of the
water over a certain heating time interval; to determine, using
said temperature increase, the duration of the observed time
interval of heating and data regarding the specific heat capacity
and the dissipative power of the heating element, the amount of
water contained in the water compartment; to compare the determined
amount of water to a maximum water amount-reference value; and in
case the determined amount of water exceeds the maximum water
amount-reference value, to stop heating the water.
6. The tea maker according to claim 1, wherein the controller is
further configured: to determine, during heating the water to the
initial steeping temperature, an increase in the temperature of the
water over a certain heating time interval; to determine, using
said temperature increase, the duration of the observed heating
time interval and data regarding a specific heat capacity and a
dissipative power of the heating element, the amount of water
contained in the water compartment to compare the determined volume
of water with a minimum water volume-reference value; and in case
the determined volume of water is smaller than the minimum water
volume-reference value, to stop heating the water.
7. The tea maker according to claim 1, wherein the temperature/time
profile includes a period of boiling the water, prior to the water
reaching the initial steeping temperature, such that the
controller, in executing said temperature/time profile, is
configured to heat the water to its boiling point, before notifying
a user that the water has been heated to the initial steeping
temperature.
8. The tea maker according to claim 1, wherein the controller, upon
detection of insertion of the tea filter into the water compartment
is configured to count a predetermined steeping time and, upon
expiry thereof, to control the notification means to notify the
user that steeping has been completed and the tea is ready for
consumption.
9. The tea maker according to claim 1, wherein the
tea-filter-presence sensor includes a magnet, connected to the tea
filter, and a reed switch disposed in or adjacent the water
compartment.
10. The tea maker according to claim 8, wherein the Controller is
configured not to heat the water in the water compartment during
the time said steeping time is counted.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to electric tea making
appliances, and more in particular to a semi-automatic tea
maker.
BACKGROUND
[0002] WO 2009/109,011-A1 (Siu) discloses a semi-automatic tea
maker. The tea maker is able to heat water contained in a vessel to
a variety of user-selectable brewing temperatures, prompt a user to
initiate a tea brewing operation (by lowering tea leaves into the
water) when the water is at the selected temperature, prompt the
termination of the tea brewing process when a user-selectable
brewing duration has passed, and subsequently maintain the water at
a drinking temperature that is lower than the brewing
temperature.
[0003] Although the tea maker according to WO'011 may facilitate
the making of tea, or at least provide a reasonable degree of user
control over the tea brewing process, its functionality leaves to
be desired. It is therefore an object of the present invention to
overcome one or more of the drawbacks associated with the tea maker
according to WO'011, as detailed below.
SUMMARY OF THE INVENTION
[0004] A first drawback associated with the tea maker according to
WO'011 relates to its behavior immediately following the action of
heating the water to the desired brewing temperature. Once the
water in the vessel of the tea maker reaches this brewing
temperature, an alert or indicator lets a user know that it is
appropriate to lower the tea into the water. The user, however, may
be momentarily occupied or otherwise unable to respond to the alert
or indicator. The tea maker according to WO'011 does not provide
for any particular response to handle such a situation. In case the
tea maker would stop heating the water after having alerted the
user, a user who is slow in responding might be left with water
that is too cold to properly brew tea. On the other hand, in case
the tea maker would indefinitely continue to heat the water, it
would never stop consuming electric energy, even though the thought
of brewing tea may have been long forgotten by the user.
[0005] To overcome this problem, a first aspect of the present
invention is directed to a tea maker that comprises a water
compartment; a tea filter that is at least partly insertable into
the water compartment; a heating element, configured to heat water
contained in said water compartment; a temperature sensor,
configured to generate a reference signal reflecting the
temperature of the water contained in said water compartment; a
tea-filter-presence sensor, configured to detect insertion of the
tea filter into the water compartment; user notification means; and
a controller that is operably connected to the heating element, the
temperature sensor, the tea-filter-presence sensor and the
notification means. The controller is configured to heat water
contained in the water compartment in accordance with a
predetermined temperature/time profile that is at least partly
defined by an initial steeping temperature; to detect whether the
water has been heated to the initial steeping temperature in
accordance with the predetermined temperature/ time profile; to
notify a user by means of the notification means that the water has
been heated to the initial steeping temperature in accordance with
the temperature/time profile and that steeping may be initiated by
insertion of the tea filter into the water compartment; and once
the user has been notified to insert the filter, to maintain the
temperature of the water within a certain range of the initial
steeping temperature until either a certain waiting period lapses,
or insertion of the tea filter is detected by means of said
tea-filter-presence sensor within said waiting period.
[0006] The tea maker may thus keep the water at or close to, i.e.
preferably within 5.degree. C. of, the selected initial steeping
temperature for a certain waiting period, starting at the point in
time at which the tea maker notifies the user that the tea filter
(holding the tea leaves) may be inserted into the water compartment
to commence steeping. The waiting period may preferably not be too
long, and safeguards that the tea maker effectively shuts itself
off once it appears to have been forgotten. On the other hand, the
waiting period may preferably not be too short either, allowing a
user to resume the tea brewing process even after temporarily
attending to different matters. Accordingly, in a preferred
embodiment, the waiting period during which the controller is
configured to maintain the temperature of the water within a
certain range of the initial steeping temperature, may be no more
than 60, and preferably no more than 30 minutes, e.g. 5-15 minutes.
The controller may be fitted with a timer or countdown counter to
track the lapse of the waiting period. When the waiting period
lapses without prior detection of insertion of the tea filter, the
controller may stop the heating element from further heating the
water and/or shut off the tea maker altogether.
[0007] A second drawback embodied by the tea maker according to
WO'011 lies in the fact that a user may accidentally or
purposefully `overfill` the vessel with water. In such a case, the
water level may reach the base of a spout connected to the water
compartment, or even higher. In particular when the temperature is
set to the boiling temperature of the water, i.e. typically
100.degree. C., the spout may spit out virtually boiling droplets
of water during heating. Subsequently pouring the hot tea from the
overfilled vessel may additionally lead to an irregular stream of
splashing liquid. Both the spitting and the splashing of the hot
tea may give rise to the risk of scalds, which is obviously
undesirable.
[0008] To overcome this problem, the controller of the tea maker
may be configured to determine, during heating the water to the
initial steeping temperature, an increase in the temperature of the
water over a certain heating time interval; and to determine, using
said temperature increase, the duration of the observed heating
time interval and data regarding the specific heat capacity of
water and the dissipative power of the heating element, the amount
of water contained in the water compartment; to compare the
determined amount of water with a maximum water amount-reference
value; and in case the determined amount of water exceeds the
maximum water amount-reference value, to stop heating the water.
The amount of heat/energy Q required to raise the temperature of a
mass of m kilograms of water by .DELTA.T degrees Celsius is
dependent on the specific heat capacity c of water, which is about
4.18 Joule/gram.degree. Celsius. The time .DELTA.t it takes to heat
the mass of water by .DELTA.T degrees Celsius is furthermore
dependent on the dissipative power P of the heating element used to
supply the heat. Mathematically, the relation between these
variables may be expressed as:
Q=P.DELTA.t=cm.DELTA.T (1)
The controller of the tea maker may be programmed with knowledge of
the values of P and c. Using an internal timer to monitor the lapse
of a representative period of heating time .DELTA.t, e.g. 10-50
seconds, and measuring the increase in water temperature .DELTA.T
that occurs during this period of heating by means of the
temperature sensor, the controller may calculate the amount of
water contained in the water compartment, either in units of mass
(e.g. kilograms), units of volume (e.g. liters; obtainable from m
by dividing it by the density of water per liter), or any other
suitable unit. The controller may subsequently compare the
calculated amount of water with a pre-programmed reference value
that represents the maximum, water compartment-specific amount of
water that can be heated and poured safely. In case the controller
finds that the amount of water contained in the water compartment
exceeds the safe maximum, it may stop the heating of the water, and
notify the user.
[0009] Instead of or in addition to an overfill protection, the tea
maker according to the present invention may include an underfill
protection. After all, an underfill situation of the vessel may
damage the tea maker due to overheating of the heating element that
is unable to give off its heat.
[0010] In one embodiment of the tea maker, the controller may thus
be configured to determine, during heating the water to the initial
steeping temperature, an increase in the temperature of the water
over a certain heating time interval; and to determine, using said
temperature increase, the duration of the observed heating time
interval and data regarding the specific heat capacity of water and
the dissipative power of the heating element, the amount of water
contained in the water compartment; to compare the determined
volume of water with a minimum water volume-reference value; and in
case the determined volume of water is smaller than the minimum
water volume-reference value, to stop heating the water.
[0011] A third drawback of the tea maker according to WO'011
concerns the manner in which it heats water to a selected brewing
temperature: whenever a brewing temperature lower than 100.degree.
C. (212.degree. F.) is selected, the water is heated to the
selected temperature without boiling it. Thermostatic control over
the water temperature prevents the water in the vessel from
exceeding the brewing temperature.
[0012] It is known that boiling tea water for too long may deplete
the water's oxygen content. And since the oxygen dissolved in the
water may be considered crucial to the tea developing its full
flavor, using water that has boiled for too long to brew tea is not
recommendable. However, using unboiled water to brew tea may also
be advised against in many parts of the world, due to the
possibility of the water containing disease-causing germs. In
addition, using unboiled water may result in tea scum on top of a
cup of freshly brewed tea.
[0013] To overcome these problems, the temperature/time profile
according to which the water is to be heated may be defined to
include a brief period of boiling the water prior to reaching the
initial steeping temperature. In executing said temperature/time
profile, the controller may then heat the water to its boiling
point before notifying a user that the water has been heated to the
initial steeping temperature. The brief period during which the
temperature of the water is maintained at its boiling point may
typically be in the range of 1-30 seconds.
[0014] According to an elaboration of the invention, the controller
may be configured to start counting a predetermined steeping time,
upon detection of tea filter insertion in the water compartment,
and, upon expiry of said steeping time, to control the notification
means to notify the user that steeping has been completed and the
tea is ready for consumption.
[0015] Once the controller detects the insertion of the tea filter
in the water compartment, the heating phase of the tea brewing
processes ends and the steeping phase starts. The steeping phase
may have a pre-determined, tea-type-specific duration, here
referred to as the steeping time, which may be counted by the
controller. When the steeping time expires, the tea brewing process
is complete, and the tea is ready for consumption.
[0016] From the foregoing it will be clear that the initial
steeping temperature is the temperature of the water in the water
compartment at the start of the steeping phase. It is known that
the optimal (initial) steeping temperatures may vary for different
types of tea. Black tea, for example, may preferably be brewed at a
water temperature close to 100.degree. C., while green tea may be
best brewed at a temperature in the range of 70-80.degree. C. A
consequence of these relatively high steeping temperatures is that
the freshly brewed tea, at the end of the steeping process, may be
relatively hot, often too hot to drink. To promote the ready
drinkability of freshly brewed tea, the controller of the tea maker
may preferably be configured so as not to heat the water during
steeping. That is, from the point that the tea filter is inserted
into the water compartment, and steeping of the tea commences, the
controller may preferably refrain from heating the water, until the
predetermined steeping time has lapsed. This allows the water to
cool slightly during steeping, such that, at the end of the
steeping process, the brewed tea has a temperature that is at, or
at least closer to, a safe and pleasant drinking temperature.
Another benefit of refraining from heating during the steeping
phase is that sugary content of the tea is less likely to
caramelize against heated parts of the tea maker.
[0017] It is noted that although the underfill and overfill
protection functionality have been described in the context of a
tea maker that is configured to maintain water at or close to the
initial steeping temperature prior to starting the steeping phase,
this functionality may be implemented in tea makers without the
latter feature.
[0018] Accordingly, it is understood that the present text also
discloses a tea maker comprising a water compartment; a heating
element, configured to heat water contained in said water
compartment; a temperature sensor, configured to generate a
reference signal reflecting a temperature of the water contained in
said water compartment; and a controller that is operably connected
to the heating element and the temperature sensor. The controller
may be configured to determine, during heating the water to the
initial steeping temperature, an increase in the temperature of the
water over a certain heating time interval and to determine, using
said temperature increase, the duration of the observed heating
time interval and data regarding a specific heat capacity and
dissipative power of the heating element, the amount of water
contained in the water compartment. In a tea maker featuring an
overfill protection functionality, the controller may further be
configured to compare the determined amount of water with a maximum
water amount-reference value; and in case the determined amount of
water exceeds the maximum water amount-reference value, to stop
heating the water. In a tea maker featuring an underfill
protection, the controller may alternatively or additionally be
configured to compare the determined volume of water with a minimum
water volume-reference value; and in case the determined volume of
water is smaller than the minimum water volume-reference value, to
stop heating the water. A tea maker including an underfill and/or
overfill functionality may be combined with any tea maker features
or embodiments described in this text.
[0019] These and other features and advantages of the invention
will be more fully understood from the following detailed
description of certain embodiments of the invention, taken together
with the accompanying drawings, which are meant to illustrate, not
limit, the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a schematic cross-sectional side view of an
exemplary tea maker according to the present invention, including a
vessel and a power base;
[0021] FIG. 2 is a schematic exploded view of the power base of the
tea maker shown in FIG. 1, illustrating its layered
composition;
[0022] FIG. 3. is a schematic top view of the power base of the tea
maker shown in FIG. 1, illustrating its user interface panel;
[0023] FIG. 4. is a schematic cross-sectional side view of a
capacitive button of the interface panel (FIG. 4A), and a
projection display of the interface panel (FIG. 4B);
[0024] FIG. 5 is a table, schematically illustrating in
cross-sectional side views of the capacitive buttons and the
projection display of the interface panel, different constructive
embodiments in case a wooden top layer is used; and
[0025] FIG. 6 is a graph illustrating a number of tea-type-specific
temperature/time profiles that may be associated with the brewing
process symbols on the user interface panel shown in FIG. 2.
DETAILED DESCRIPTION
[0026] FIG. 1 is a schematic cross-sectional side view of an
exemplary tea maker 100 according to the present invention. The tea
maker 100 may comprise two main, detachably connectable components:
a vessel 200 and a power base 300. The vessel 200 may include a
main body 202. In the embodiment of FIG. 1, the main body 202 is
depicted as a single-walled structure. It is contemplated, however,
that a different embodiment of the tea maker 100 may feature a
vessel 200 having a double-walled main body 202, in particular to
improve thermal insulation of the interior of the vessel. In either
case, the main body 202 may be provided with a handle 204 for
managing it. The handle 204 may be connected to the main body 202
through a body of thermally insulative material 205 to prevent
excessive heating of the handle during use. A watertight partition
208 may divide the interior of the vessel 200 into a water
compartment 210 and a lower compartment 212. The water compartment
210 may extend between the top of the vessel 200 and the watertight
partition 208, whereas the lower compartment 212 may extend between
the watertight partition and the underside of the vessel. A
flexible bridge 209, e.g. a relatively thin annular slab of metal,
may be used to connect, e.g. by welding, the water tight partition
208 to an inner side or wall of the main body 202, so as to
accommodate thermal expansion and/or contraction of the different
parts during operation.
[0027] The water compartment 210 may be accessible via a central
opening 214 in the upper side of the vessel 200 that is coverable
by a hinged or detachable lid 220. The vessel 200 may also be
provided with a spout 206 that allows water to be poured out from
the water compartment 210.
[0028] The opening 214 may be shaped to receive a removable tea
filter 216, which may include an at least partly liquid-permeable,
for example meshed, basket 217 that can be lowered into the water
compartment 210. The basket 217 may be made of any suitable
material, but is preferably made of stainless steel. The mesh or
alternative liquid-permeable features of the basket 217 may be fine
enough to hold tea leaves during steeping, and for example include
openings having a diameter in the range of 0.1-0.5 mm. The filter
216 may also be fitted with a permanent magnet 218, which may be
attached to or incorporated into the bottom part of the basket 217.
This may allow the magnet's 218 presence, and hence tea filter's
216 presence, in the water compartment 210 to be detected by a reed
switch 226 provided in the lower compartment 212.
[0029] The lower compartment 212 may accommodate a for example
arc-shaped electric heating element 222 that may be attached to the
underside of the partition 208, which forms the bottom of the water
compartment 210. The heating element 222 may have a dissipative
power output suitable for heating a filled up water compartment 210
within about 2-5 minutes, e.g. 1 to 3 kW. To promote the transfer
of heat from the heating element 222 to the water in the water
compartment 210, the partition 208 may be made of a material with a
good thermal conductivity, such as aluminum or copper, allowing it
to act as a heat diffuser.
[0030] The partition 208 may include a central opening through
which a temperature sensor 224, e.g. an NTC thermistor, extends
from the lower compartment 212 into the water compartment 210. A
seal, e.g. a silicone O-ring, may be provided to ensure the
watertightness of the partition 208 at the temperature sensor's
position. Alternatively, a temperature sensor 224 may be located
below/against an underside of the partition 208, so as to measure
the temperature in the water compartment 210 through partition 208,
thereby eliminating the need for a water-sealing component.
[0031] The lower compartment 212 may further accommodate a reed
switch 226 that is configured for cooperation with a permanent
magnet 218 provided on or incorporated in the removable tea filter
216. The reed switch 226 and the magnet 218 may be disposed such
that the reed switch is actuated by the magnetic field of the
magnet when the tea filter 216 is placed in the vessel 200, giving
it the function of a proximity sensor or, more specifically, a tea
filter presence sensor. To promote the detectability of the tea
filter 216, using only a single reed switch 226 and a single magnet
218, the former may be attached to a central portion of the
watertight partition 208, and the latter may be disposed in a
central bottom area of the basket 217. This may eliminate the
sensitivity of the detection of the tea filter 216 to the angular
position in which it is placed in the water compartment 210 (the
angular position seen relative to a central, vertically extending
axis A of the tea maker 100). In particular when the reed switch
226 is fixed to the partition 208, it may be enclosed in a
thermally insulating casing, e.g. a silicone tube, that spaces it
apart from both the partition and the heating element 222
sufficiently to prevent overheating.
[0032] Although a magnet 218 and a reed switch 226 may form a
reliable and cost-effective tea-filter-presence sensor, it is
contemplated that an alternative embodiment of the tea maker 100
may include a different (i.e. non-magnetic) type of sensor for
detecting insertion or placement of the tea filter 216 in the water
compartment 210 of the vessel 200, such as an optical sensor, e.g.
a light source in combination with a photo detector, or a
mechanically operated sensor, e.g. a pressure switch. In principle,
any sensor suitable for the stated purpose may be used.
[0033] A central recess 228 in the bottom of the vessel 200 may
grant access to a vessel portion 230a of an electric, for example
5-pole, connector 230. The vessel portion 230a of the connector 230
may be mounted to a bottom side of the partition 208, and be
configured for functional engagement with a complementary power
base portion 230b of the connector. When the vessel 200 rests on
the power base 300, and the two connector portions 230a, 230b are
in mutual engagement, power and data signals may be exchanged
between the power base and the vessel through the connector 230. It
is understood that all electrical components in the vessel 200
(including the electric heating element 222, the temperature sensor
224 and the reed switch 226) may be electrically connected to the
vessel portion 230a of the electric connector, but the necessary
wires have been omitted from the drawings for reasons of
clarity.
[0034] The construction of the power base 300 is best illustrated
with reference to both FIG. 1 and FIG. 2, the latter showing a
schematic exploded view of the power base that illustrates its
generally layered composition.
[0035] The power base 300 may include a main body 302. In the
depicted embodiment, the main body 302 is a generally bowl-shaped,
injection molded plastic shell. An underside of the main body 302
may be shaped to define an annular recess 304 for storing a power
cord 306. To prevent a wound and stored power cord 306 from
dropping out of the recess 304, a radial inner portion of the
annular recess 304 may be covered by a bottom cap 308 that may be
fixed to the main body 302 by screwing. The main body 302 of the
power base 300 may further include a mounting plateau 310. The
mounting plateau 310 may include a centrally disposed, upright
annular ridge 312 on which the power base portion 230b of the
electrical connector 230 may be installed. A more radially outward
portion of the mounting plateau may support an annular printed
circuit board (PCB) 320. The PCB 320 may mechanically support and
electrically connect a number of components, including: [0036] a
plurality of independently controllable first illumination means
322, in particular light emitting diodes (LEDs). The first
illumination means 322 may preferably be equidistantly spaced along
a circular or otherwise shaped path surrounding the central opening
of the annular PCB 320. As will be elucidated below, the first
illumination means 322 may cooperate with an annular light guide
340, to be disposed on top of the PCB 320, in order to form a
illuminable ring-shaped brewing progress indicator 368 of an
interface panel 360 of the tea maker 100; the interface panel 360
and progress indicator 368 are best shown in FIG. 3. The LEDs of
the first illumination means 322 may be coupled and arranged to the
PCB 320 such that their light 323, as illustrated in FIG. 1, is
emitted in a substantially radially outward direction, which may be
substantially parallel to the plane of the illuminable ring-shaped
brewing progress indicator 368. The first illumination means 322
may comprise LEDs of a single color or LEDs of multiple colors,
possibly in the form of multi-color LEDs. The exemplary embodiment
of the tea maker 100 illustrated in FIGS. 1-2 includes twenty-four
first illumination means 322 in the form of LEDs; it is
contemplated, however, that different embodiments of the tea maker
100 may include a different, smaller or larger, number of first
illumination means 322. [0037] a plurality of capacitive sensors
326, one for each capacitive button 362 of the interface panel 360.
In the depicted embodiment, the capacitive sensors 326 are shown as
capacitive coils, one for each of the eight capacitive buttons 362.
[0038] a plurality of independently controllable second
illumination means 324, in particular LEDs, disposed adjacent the
capacitive sensors 326 and configured to illuminate the respective
associated capacitive button 362. In the depicted embodiment, two
LEDs 324 are disposed on opposite sides of each capacitive sensor
326. [0039] a plurality of independently controllable third
illumination means 328, in particular LEDs, for illuminating a
projection display 370 that is best shown in FIG. 3. In the
depicted embodiment, the projection display 370 includes one
two-segment and two seven-segment indicators, which together are
capable of indicating numeric values from 0 to 199. Altogether, the
third illumination means 328 may thus be comprised of sixteen LEDs.
In case the projection display includes additional indications,
e.g. a ".degree. C."-indication or a "min."-indication for
temperature and time, respectively, each of these extra indications
may be provided with its own, dedicated third illumination
means/LED(s). [0040] a loudspeaker 330 or other suitable
electroacoustic transducer, capable of generating sound to notify a
user. [0041] a central controller 332. The controller 332 may be
operably connected to all the electric components in the power base
300, and when the vessel 200 is placed on the power base such that
the two connector portions 230a, 230b are in mutual engagement,
said controller may also be operably connected to the electric
components in the lower compartment 210 of the vessel 200. In
addition, the controller 332 may typically include a processor or
an integrated circuit capable of executing a certain program or
series of instructions, so as to enable it to perform the actions
described in this text. The construction and use of integrated
circuits is well known in the art, and will not be elaborated
upon.
[0042] As is clearly visible in FIG. 2, the PCB 320 may be topped
with a series of annular (i.e. having a central opening for
encompassing the base portion 230b of the electric connector 230),
more or less disc-shaped components. In upward order these
components include: a light guide 340, a focusing mask 350, a
transparent body 354, a masking layer 356 and a diffusion layer
358.
[0043] The light guide 340 may comprise a ring of an optically
transmissive material, such as glass or a transparent plastic, e.g.
polycarbonate or polymethyl methacrylate (better known as acrylic
glass, or PMMA). The ring may have a wavy or sinuate inner
circumferential edge 342, with a number of equidistantly spaced,
radially inwardly extending protrusions 344, one for each of the
first illumination means 322. In an assembled condition, the
radially inwardmost edges or tips of the protrusions 344 may abut
the light-emitting surfaces of the first illumination means 322,
allowing them to couple light into the light guide 340. An upper,
outwardmost edge of the light guide may form a light escape strip
346. To allow light, coupled into the light guide 340 by the first
illumination means 322, to escape from the guide via the light
escape strip 346, the exterior surface of the strip may be suitably
treated, for example by abrasion, bending, or notching. Such a
treatment may frustrate the total internal reflection at the
exterior surface boundary of the strip 346, and thus permit at
least a fraction of the light incident on the boundary to be
transmitted therethrough.
[0044] The focusing mask 350, which may have an inner opening
sufficiently large to encompass the light guide 340, may include a
ring with a number of opaque, for example black-colored light
containers 352 attached thereto (see also FIGS. 4A,B). A light
container 352 may be associated with either a capacitive button
362, or with a segment indicator of the projection display 370.
Each of the light containers 352 associated with a capacitive
button 362 may be generally jacket shaped, so as to form a light
chamber in which both the second illumination means 324 and the
capacitive sensor 326 of the respective button can be enclosed (see
FIG. 4A). The light containers 352 associated with the projection
display 370 may comprise a number of substantially vertically
extending slots 353. Each of the slots 353 may define a single
segment 372 of the projection display, and be uniquely associated
with one or more of the third illumination means 328 (see FIG. 4B).
The upper edges of the walls of the light containers 352, in
particular those associated with the projection display 370, may
extend a little inward (shown in FIG. 4B), so as to form a
well-defined opening in the light-emitting end of the light
container 352 that helps shape the cone of light that can escape
therefrom. In fact, such inwardly extending edges may fulfill the
function of a mask, and locally replace the masking layer 356 to be
discussed below. The light containers 352 may be relatively high,
e.g. about 10 mm, to ensure that light emitted by the second and
first illuminations means 324, 328 at the base of the light
containers, in a direction that is not at least approximately
perpendicular to the plane of the PCB 320 on which they are
mounted, is absorbed by the black-colored walls of the
containers.
[0045] On top of the focusing mask 350, in succession, the
transparent body 354, the masking layer 356 and the diffusion layer
358 may be provided. Although FIG. 2 shows these items as separable
parts, they may preferably be integrated. That is, the transparent
body 354 may serve as a mechanical carrier, on an upper side of
which the relatively thin masking layer 356 and light diffusion
layer 358 may be applied, in that order.
[0046] The transparent body 354 may include an annular disc made of
a transparent and mechanically strong material, such as glass or
polycarbonate. The disc may have a thickness on the order of
millimeters. Its upper side may be coated with a thin, opaque
masking layer 356. The masking layer 356 may have a thickness on
the order of tens of micrometers, and be applied to the transparent
body, using a conventional coating technique, such as screen
printing. At the locations associated with the ring-shaped brewing
progress indicator 368, the capacitive buttons 362 and the
projection display 370, the masking layer 356 may comprise
transparencies 357 that, individually or in groups, define
illuminable symbols 364, 366 or segments 372 of the interface panel
360. In the depicted embodiment, the entire area of the masking
layer 356 associated with the projection display 370 is transparent
(instead of multiple areas, each associated with single segment
372), which is possible because the masking function for the
projection display 370 is performed by the inwardly extending top
edges of the walls of the light container 352 of the display (see
FIG. 4B). The masking layer 356, in turn, may be covered with a
light diffusion layer 358. The primary function of the light
diffusion layer 358 is that of a projection screen, on which the
patterns of the masking layer 350 can be imaged when backlit by the
second and third illumination means 324, 328 provided on the PCB
320. The light diffusion layer 358 may further act as a
wear-resistant, preferably watertight, varnish. To serve both
purposes, the light diffusion layer 358 may be composed of a
conventional lacquer comprising light scattering pigment particles
of, for example, titanium dioxide or barium sulphate. In order to
facilitate sharp projections and prevent complete opacity, the
light diffusion layer may generally have a thickness smaller than
about 0.1 mm.
[0047] In one embodiment of the tea maker 100, the diffusion layer
358 may be made of wood; in such an embodiment the wooden diffusion
layer is referred to with reference numeral 359. Wood is a natural
material with a calming aura that fits in with the naturalness and
culture of tea, and may therefore be a material of choice. It is,
however, also opaque. FIGS. 5A and 5C schematically illustrate how
symbols 364, 366 of capacitive buttons 362 may nevertheless be made
visible on the user interface panel 370. It is understood that,
although FIG. 5 depicts the construction of capacitive buttons 362,
it is, mutatus mutandis, equally applicable to the segments 372 of
the projection display 370 and other indicators, such as an
illuminable brewing progress indicator 368, on the user interface
panel 360. The wooden diffusion layers 359 of FIGS. 5A and 5C may
both be manufactured by providing a slab of wood or wood veneer,
for example having a thickness on the order of millimeters, and
selectively milling or otherwise reducing it to a thickness on the
order of several tenths of millimeters, e.g. 0.1-0.4 mm, at the
locations corresponding to illuminable portions of the symbols 364,
366, the segments 372 and/or the brewing progress indicator 368. At
thicknesses of tenths of millimeters, the wood becomes translucent,
such that light emanating from the first, second and/or third
illumination means 322, 324, 326 may shine through it, and the wood
may act as a diffusion layer.
[0048] In FIG. 5A, the thickness of the wooden slab has been
selectively reduced by removing material from the front or outer
side thereof, while in FIG. 5C, material has been removed from the
back or inner side. Both embodiments offer the advantage that the
diffusion layer 359 remains a closed layer, having no perforations
through which moisture may easily access the power base 300.
However, in case it is desired that the diffusion layer has a
smooth or flat front surface without notches or recesses, such as
in the case of a `dead panel` user interface, the embodiment of
FIG. 5C may be preferred.
[0049] With reference to the layered construction of the power base
300, it is noted that in embodiments comprising a wooden diffusion
layer, the masking layer 356 shown in FIG. 2 may be omitted from
the construction of the tea maker 100 or disposed on the other side
(i.e. the bottom side) of the transparent body 354. In some
embodiments, in particular those not featuring a masking layer 356
provided against the bottom or inner side of the wooden diffusion
layer 359, a translucent white layer may be attached to the back
side of the wooden diffusion layer in order to enhance the
visibility of the illuminated symbols 364, 366, segments 372 or
brewing progress indicator 368. Such a translucent white layer may
be pad printed, lacquered, screen printed or otherwise provided on
the back side of the wooden diffusion layer 359.
[0050] The transparent body 354 itself may be manufactured and
attached to the wooden diffusion layer 359 by means of insert
molding. In the embodiment of FIG. 5C, the resin used for the
insert molding process may at least partially fill up the recesses
in the back side of the wooden diffusion layer 359, and thus
provide mechanical back support for the thinned, translucent
portions thereof.
[0051] For comparison, FIG. 5B illustrates an alternative
embodiment that may be manufactured in a generally similar manner
as the embodiments of FIGS. 5A and 5C, except that (through-)holes
or perforations may be milled in the slab of wood. The construction
of FIG. 5B may also be used for the symbols 366, 364, the segments
372 and/or the brewing progress indicator 368, but may generally be
less preferred because small perforations may prove difficult to
fill with resin during insert molding of the transparent body 354,
as air may be entrapped in the cavities. In addition, it will be
clear that, due to the perforations, the wooden top layer in the
construction of FIG. 5B may not actually serve as a diffusion
layer. This implies that it is less suitable for creating `dead
panel` user interfaces, since the perforations of the wood would be
visible on the interface panel 360 at all times.
[0052] FIG. 3 is a schematic top view of the power base 300 of the
tea maker 100, illustrating its user interface panel 360. It will
be clear from the foregoing that the user interface panel 360 may
be a so-called `dead panel`. That is, its visible surface may not
include any permanent marks, and the symbols 364, 366, segments 372
and brewing progress indicator 368 shown in FIG. 3 may be visible
only when actively illuminated by the internal first, second and
third illumination means 322, 324, 328. Accordingly, the user
interface panel 360 may appear blank in the case that the tea maker
100 is unplugged from the mains.
[0053] The user interface panel 360 may feature a number of
juxtaposed capacitive buttons 362, each provided with its own
symbol 364, 366. From left to right, the panel 360 depicted in FIG.
3 includes: a power on/off button, four pre-programmed brewing
program selection buttons (to the left of the projection display
370), two display input buttons (one on either side of the
display), and one programmable brewing program selection button (to
the right of the projection display 370). To the right of the
latter brewing program selection button, the user interface panel
360 includes a filter placement indicator, which is not a button
but merely an illuminable icon.
[0054] The power on/off button, the two display input buttons and
the filter placement indicator may each be provided with a
functional symbol 366. The functional symbol 366 of the power
on/off button may preferably be conventional for ease of
recognition by the user, and may, if desired, be pad printed or
laser engraved in or on the diffusion layer 358, 359, or made like
a burn mark by a laser process, instead of being provided in the
structure of the masking layer 356 as described above. The same
applies to the two display input buttons, which in the embodiment
depicted in FIG. 3 are provided with functional symbols in the form
of a solid left-pointing and a solid right-pointing triangle. Their
purpose is to enable a user to manipulate the figures shown on the
display. The brewing program selection buttons may each be provided
with a brewing program symbol 364. As will be explained below, the
controller 332 of the tea maker 100 may assign a tea-type-specific
brewing program to each of these symbols 364. The brewing program
symbols 364 themselves may preferably be non-numeric and
non-alphabetic, so as to reduce a user's perception that he is
dealing with a complicated technological device. The use of
pictorial symbols may also reduce the manufacturing costs involved
in producing the tea maker 100 for different localities. For
example, in the case of alphabetic labels, a button 362 might have
to mention "Black tea" in England, "Schwarztee" in Germany, and
"The noir" in France, while in the case of a pictorial symbol, the
button might be the same for all these countries. Furthermore, the
brewing program symbols 364 may preferably be comprised of
separate, approximately circular dots, setting them apart from the
continuous-line symbols typically found on conventional
apparatus.
[0055] Besides the capacitive buttons 362 and the filter placement
indicator, the user interface panel 360 may also feature a
projection display 370 and a ring-shaped brewing progress indicator
368. The area of the user interface panel 360 bounded by the
brewing progress indicator 368 may define a vessel reception
location 361 for receiving the vessel 200, as shown in FIG. 1.
[0056] The brewing progress indicator 368 may be illuminated by the
first illumination means 322, whose light may be successively
transmitted through the light guide 340, the transparent body 354,
the respective transparencies 357 in the masking layer 356, and
onto the light diffusion layer 358. The construction of the light
guide 340 may preferably be such that the brewing progress
indicator 368 may be considered to be comprised of a series of
interconnected transparent sections, each of which may be lit
independently of the others by switching the associated first
illumination means 322 on or off. Although the brewing progress
indicator 368 may in principle have any suitable shape, it may
preferably be substantially circle segment-shaped or ring-shaped.
Therefore, it may extend around a center of the user interface 360,
e.g. along a perimeter of an inner edge of the user interface panel
360, at a distance therefrom. The inner diameter of the brewing
progress indicator 368 may preferably be greater than an outer
diameter of (at least the bottom of) the vessel 200. In such an
embodiment, the brewing progress indicator 368 may surround a
vessel 200 placed on the power base 300 at the vessel reception
location 361, such that, in a fully illuminated state, it is still
at least partly (typically about one half) visible to a user at any
position next to the tea maker 100.
[0057] Now that the construction of the tea maker has been
described in some detail, attention will be given to its
operation.
[0058] A brewing process to be executed by the tea maker 100 may
typically comprise the following series of steps:
[0059] 1. Brewing program selection
[0060] 2. Heating water to selected initial steeping
temperature
[0061] 3. Tea filter placement
[0062] 4. Steeping tea for selected steeping time
[0063] 5. Notifying user that tea is ready
[0064] Brewing program selection involves the choice of a tea
brewing program by the user, wherein `brewing program` refers to a
certain temperature/time profile to be followed by the water
contained in the water compartment 210 of the vessel 200 during the
tea brewing process. A temperature/time profile may typically
involve at least two consecutive phases: a heating phase (step 2)
and a steeping phase (step 4). During the heating phase, the water
in the vessel 200 may be heated to an initial steeping temperature.
Heating of the water may include boiling it, but this is not
necessary. For example, in case the initial steeping temperature is
set to 80.degree. C., water may be heated from room temperature up
to 80.degree. C. directly, e.g. along an approximately straight
temperature/time-path. Alternatively, the water may first be boiled
and then cooled or left to cool to 80.degree. C. Once the water has
attained the set initial steeping temperature, the steeping phase
of the tea may be initiated by placement of the tea filter (step
3). The duration of the steeping phase is given by the steeping
time. When the steeping time has elapsed, the tea is ready for
consumption (step 5).
[0065] A temperature/time profile outlined above may include three
defining parameters that may differ for different types of tea: the
initial steeping temperature (a temperature value), a pre-steep
boiling flag that controls whether or not the water is heated to
its boiling point before steeping (a Boolean value, true of false),
and the steeping time (a time value). The controller 332 of the tea
maker 100 may assign a value for one or more of these parameters to
a brewing program symbol 364 of the user interface panel 360, so as
to define the brewing program associated therewith.
[0066] FIG. 6 illustrates four temperature/time profiles I, II,
III, IV that may be associated with the four pre-programmed brewing
program selection buttons of the user interface panel 360 shown in
FIG. 3. The leftmost brewing program selection button, featuring a
brewing program symbol in the form of a fully illuminated tea leaf,
may for example be associated with a brewing program for black tea.
The controller 332 may accordingly assign the values 100.degree.
C., true, and 2 minutes to the initial steeping temperature, the
pre-steep boiling flag and the steeping time, respectively. The
second brewing program selection button from the left, featuring a
symbol in the form of a edge-lit tea leaf, may likewise be
associated with a brewing program for green tea, and the controller
332 may successively assign the values 80.degree. C., true, and 2
minutes to the aforementioned variables, in that order. The third
and fourth symbols from the left, having the shape of a flower and
a rooibos plant respectively, may in turn be associated with
brewing programs for respectively herbal tea and rooibos tea. The
controller 332 may assign the values 100.degree. C., true, and 7
minutes to the former brewing program symbol, and the values
100.degree. C., true and 5 minutes to the latter. FIG. 6
graphically illustrates these assignments. It is understood that
the above-described assignments are exemplary only, and that, in
principle, any combination of values may be assigned to any brewing
process symbol.
[0067] To enable the selection of a brewing program by the user,
the controller 332 may suitably illuminate the brewing program
selection symbols 364 in the user interface panel 360 by powering
the associated second illumination means 324. The controller 332
may, for example, first illuminate all symbols 364, in order to
present the user with all available options, and then keep only a
selected symbol illuminated to provide the user feedback of the
selection. The controller 332 may, in addition or alternatively,
provide feedback to the user by making symbols 364 blink, by
changing their colors (if the second illumination means provide
light of different colors), or by generating sounds through the
loudspeaker 330 to accompany a selection.
[0068] Once a user `presses` a brewing program selection button to
select the brewing program of his choice, the controller 332 may
load the corresponding brewing parameters from its memory. In case
the user pressed a pre-programmed brewing program button, the
controller 323 may immediately proceed to step 2 of the brewing
process. Alternatively it may wait for a confirmation before
starting the heating phase (e.g. through pressing the selected
button again). In case the user pressed the user-programmable
brewing program selection button, the controller may present the
selectable parameters of the brewing program to the user via the
projection display 370 for optional review. When the user has
entered his preferences, the controller 332 may proceed to step 2
of the brewing process.
[0069] To heat the water in the vessel 200 to the initial steeping
temperature in accordance with the temperature/time profile
associated with the selected brewing program, the controller 332
may selectively switch the electric heating element 222 on and off.
Alternatively, the controller 332 may, for example, vary the power
supplied to the heating element 222, or employ a more sophisticated
PID-controller strategy. When the heating element 222 is switched
on, it may generate heat that is transferred to the water, causing
its temperature to rise. When the heating element 222 is switched
off, heat may slowly leak from the vessel 222, causing the water
temperature to drop. The water temperature itself may be measured
by means of the temperature sensor 224. Accordingly, the controller
332 may control and monitor the progress of the heating phase, and
once the selected initial steeping temperature is reached, it may
notify the user that the tea filter 216 may be placed (step 3 of
brewing process), e.g. by suitably illuminating the filter
placement indicator on the user interface panel 360.
[0070] As a safety feature, the heating step may include an under-
and/or overfill protection. An underfill situation occurs when
there is no or a too small amount of water in the water compartment
210 during the heating phase. In the event that an underfill
situation remains undetected, it may result in an overheated
heating element 222 due to the fact that the element is
insufficiently capable to give off its heat. An overfill situation,
by contrast, occurs when there is too much water in the water
compartment 210. The high water level that characterizes an
overfill situation may be dangerous, as rapidly heated water may
spit from the spout 206 of the vessel 200, or splash against its
lid 220. To detect an overfill situation, the controller 332 of the
tea maker 100 may be configured to determine, during heating the
water to the initial steeping temperature, a temperature increase
of the water over a certain heating time interval; and to
determine, using said temperature increase, the duration of the
observed heating time interval and data regarding the specific heat
capacity of water and the dissipative power of the heating element,
the amount of water contained in the water compartment 210; and to
compare the determined amount of water with a maximum water
amount-reference value; and in case the determined amount of water
exceeds the maximum water amount-reference value, to stop heating
the water. To detect an underfill situation, the controller 332 may
similarly be configured to compare the determined volume of water
with a minimum water volume-reference value; and in case the
determined volume of water is smaller than the minimum water
volume-reference value, to stop heating the water.
[0071] The amount of heat Q required to raise the temperature of a
mass of m kilograms of water by .DELTA.T degrees Celcius is
dependent on the specific heat capacity c of water, which is about
4.18 Joule/gram.degree. Celcius. The time .DELTA.t it takes to heat
the mass of water by .DELTA.T degrees Celcius is furthermore
dependent on the dissipative power P of the heating element used to
supply the heat. Mathematically, the relation between these
variables may be expressed as:
Q=P.DELTA.t=cm.DELTA.T (1)
The controller 332 of the tea maker 100 may be programmed with
knowledge of the values of P and c. Using an internal timer to
monitor the lapse of a representative period of heating time
.DELTA.t, e.g. 10-50 seconds, and measuring the increase in water
temperature .DELTA.T that occurs during this period of heating by
means of the temperature sensor, the controller may calculate the
amount of water contained in the water compartment, either in units
of mass (e.g. kilograms), units of volume (e.g. liters; obtainable
from m by dividing it by the density of water per liter), or any
other suitable unit. In the case of an overfill protection, the
controller 332 may subsequently compare the calculated amount of
water with a pre-programmed reference value that represents the
maximum, water compartment 210-specific amount of water that can be
heated and poured safely. In case the controller finds that the
amount of water contained in the water compartment exceeds the safe
maximum, it may stop the heating of the water, and notify the user.
In the case of an underfill protection, the controller may
subsequently compare the calculated amount of water with a
pre-programmed reference value that represents a minimum, water
compartment 210-specific amount of water required to operate the
device safely. In case the controller finds that the amount of
water contained in the water compartment is smaller than the safe
minimum, it may switch off the heating element 222 to stop the
heating of the water, and notify the user.
[0072] At the time the tea maker 100 notifies the user that the tea
filter 216 may be placed, a user may be temporarily occupied and
unable to respond to the notification. To accommodate situations
like these, the controller 332 may be configured to keep the water
temperature close to the set initial steeping temperature during
the time it awaits placement of the filter 216. That is, the
controller 332 may be configured to monitor the temperature of the
water in the water compartment 210, and in case it notices that the
temperature drops below the set initial steeping temperature by
more than a predetermined value, e.g. 3.degree. C. or 5.degree. C.,
it may temporarily re-activate the heating element 222 to bring the
temperature back to the initial steeping temperature. The
controller 332 may preferably maintain the water temperature close
to the initial steeping temperature for no more than a
predetermined period of time, e.g. 5-10 minutes. If after this
period no filter 216 has been placed, the controller 332 may shut
off the tea maker 100, so as to prevent it from heating water that
appears to have been forgotten.
[0073] Placement (and removal) of the tea filter 216 (step 3) may
be detected by the controller 332 through the reed switch 226,
which may be operated by the magnet 218 provided in or on the
filter. When the controller 332 has notified the user that the tea
filter 216 may be placed, and placement of the filter is
subsequently detected, the controller may initiate the steeping
phase of the brewing process (step 4).
[0074] To this end, the controller 332 may cancel any notification
that the filter 216 may be placed, and switch off the heating
element 222. Then it may count the steeping time associated with
the selected brewing program. When the steeping time has elapsed,
it may notify the user that the tea has been brewed and is ready
for consumption (step 5).
[0075] As described, some types of tea, such as black tea, may have
a relatively high optimal steeping temperature, e.g. around
90-100.degree. C. A consequence of such high steeping temperatures
is that the freshly brewed tea, at the end of the steeping phase,
may be relatively hot, and often too warm to drink comfortably. To
promote the ready drinkability of freshly brewed tea, the
controller 332 of the tea maker 100 may preferably be configured
not to heat the water during steeping. That is, from the point that
the tea filter 216 is inserted into the water compartment 210, and
steeping of the tea commences, the controller 332 may preferably
refrain from heating the water, at least until the predetermined
steeping time has lapsed. This allows the water to cool slightly
during steeping, just like during traditional tea brewing, such
that, at the end of the steeping phase, the brewed tea has a
temperature that is at, or at least closer to, a safe and pleasant
drinking temperature. Another benefit of refraining from heating
during the steeping phase is that the sugary content of the tea
will not caramelize against heated parts of the tea maker 100, such
as the partition 208. The controller 332 may, of course, be
configured to maintain the water in the water compartment 210 at a
suitable drinking temperature, for example in the range of
60-70.degree. C., once the steeping phase has ended.
[0076] During the tea brewing process, the tea maker 100 may issue
notifications to notify a user of a variety of events, as
described. It is understood that these notifications may generally
be given in any suitable way, including suitably lighting any of
symbols 364,366 on the user interface panel 360, and/or generating
sounds through the loudspeaker 330. In addition, notifications may
be given by means of the brewing progress indicator 368. By way of
example, possible uses of the brewing progress indicator 368 for
issuing notifications will now be described in some more
detail.
[0077] As its name implies, the brewing process indicator 368 may
be used primarily to inform the user of any progress in the tea
brewing process. In this respect, it may notify a user that certain
steps or stages of the brewing process have been reached and or
(partly) completed. The operation of the brewing process indicator
368 may be controlled by the controller 332, which to this end may
be configured to control the first illumination means 322 according
to an illumination notification pattern stored in the controller
332. A notification pattern may comprise a sequence or arrangement
of different activities, such as activating and/or deactivating one
or more first illumination means 322, increasing and/or decreasing
the light intensity of one or more first illumination means,
blinking of one or more illumination means during a predetermined
time period with a predetermined frequency and setting a light
emitting color of one or more first illumination means. Although
one notification pattern may be used for all brewing programs, some
embodiments may allow a notification pattern to be uniquely
associated with a certain brewing program or tea type. In general,
each of the first illumination means 322 may be individually
controlled by the controller 332 in accordance with the
prescriptions of the notification pattern.
[0078] To inform the user of any progress in the tea brewing
process, the notification pattern may prescribe that the brewing
progress indicator 168 is gradually illuminated or filled with
light, for example by successively turning on adjacent first
illumination means 322 so as to form a gradually extending string
of light. At the start of the brewing process, the progress
indicator 368 may thus not be illuminated, whereas at the point of
completion of the brewing process, the progress indicator 368 may
be illuminated completely (forming an illuminated ring). The
notification pattern may prescribe that the brewing progress
indicator 368 is to be illuminated in one color or in multiple
colors (if provided for by the first illumination means 322), for
example to form a multi-colored arc starting in green and ending in
red.
[0079] In addition to its basic function of indicating brewing
progress by having an indicative or proportional portion of its
length illuminated, the brewing progress indicator 368 may also be
used to notify the user of certain events or to provide him with
information about the status of the tea maker 100.
[0080] For instance, at the start of the tea brewing process, the
water in the vessel 200 is heated to a predetermined initial
steeping temperature. The notification pattern may prescribe that
the first illumination means 322 are to reflect the changing
temperature of the water during this heating phase. Accordingly,
the first illumination means may for example be controlled such
that their color changes, for instance from blue when the water is
cold, to red when the water is hot. Alternatively or in addition,
the first illumination means 322 may be controlled to blink during
the heating period with a predetermined frequency that depends on
the water temperature. The first illumination means may for example
blink at a low frequency when the water is cold, and at a high
frequency when the water is hot. According to yet another
alternative, the light intensity of the light emitted by the first
illumination means 322 may be varied, from a low intensity when the
water is cold, to a high intensity when the water is hot.
[0081] In another embodiment, the brewing process indicator 368 may
be used to notify the user of filter placement (step 3 of the
brewing process). For instance by periodically or continuously
changing the color of the light that fills the brewing progress
indicator 368, the user may be made aware of the fact that the tea
filter 216 may be inserted. Alternatively, the first illumination
means 322 of the progress indicator 368 may be controlled such that
they start blinking To avoid confusion, the controller 332 may
control the first illumination means 322 such that the blinking
frequency differs from the blinking frequency that is coupled to
another notification that may be issued. Once the tea filter 216
has been placed, the brewing progress indicator 368 may continue to
show the progress of the tea brewing process in the regular
fashion.
[0082] In yet another embodiment, the brewing progress indicator
368 may be used to notify the user of the fact that tea is ready
for consumption. Such a notification may, of course, be provided by
the fact that the progress indicator 368 is completely filled with
light, but again, the notification pattern may additionally
prescribe that the first illumination means 322 are controlled such
that they start blinking, for example by gradually fading in and
out, or execute any other lighting variation mentioned above.
[0083] Apart from notifying the user of the progress in the brewing
process, e.g. that certain steps or stages have been reached, the
progress indicator 368 may also be used to inform the user of
information regarding the status of the tea maker 100. The
controller 332 may, for example, be preprogrammed such that certain
situations that may occur when using the tea maker 100 may initiate
a notification. In case of the underfill situation or the overfill
situation as described above, the tea maker 100, or at least the
heating element 222, may be automatically switched off to prevent
damage to the tea maker 100 or to prevent the occurrence of unsafe
situations. Then, the user may be informed accordingly, for
instance by means of a sound generated by the loudspeaker 330
and/or by means of the brewing progress indicator 368. Therefore,
the controller 332 may control the first illumination means 322 to
execute any of the aforementioned lighting variations. The brewing
progress indicator 368 may also be used to periodically notify the
user that the tea maker 100 needs to be cleaned or descaled.
[0084] With regard to the terminology used in this text, the
following is noted. The word `tea` is generally used broadly to
describe beverages made from the leaves of a plant. Accordingly,
the word `tea` not only refers to beverages prepared from the plant
Camellia Sinensis, but also intends to cover tisanes, herbal
infusions and the like.
[0085] Although illustrative embodiments of the present invention
have been described above, in part with reference to the
accompanying drawings, it is to be understood that the invention is
not limited to these embodiments. Variations to the disclosed
embodiments can be understood and effected by those skilled in the
art in practicing the claimed invention, from a study of the
drawings, the disclosure, and the appended claims. Reference
throughout this specification to "one embodiment" or "an
embodiment" means that a particular feature, structure or
characteristic described in connection with the embodiment is
included in at least one embodiment of the present invention. Thus,
the appearances of the phrases "in one embodiment" or "in an
embodiment" in various places throughout this specification are not
necessarily all referring to the same embodiment. Furthermore, it
is noted that particular features, structures, or characteristics
of one or more embodiments may be combined in any suitable manner
to form new, not explicitly described embodiments.
* * * * *